水稻气力式排种器分层充种室设计与试验

为改善水稻种子在充种室内的流动性并提高水稻气力式精量穴播排种器的排种精度,实现超级杂交稻(1~3)粒/穴精量穴播要求,在水稻气力式精量穴播排种器与种箱间设计了一种分层充种室。以含水率为20.3%(湿基)"培杂泰丰"超级杂交稻种子为对象,采用单因素试验和正交试验的方法,研究了不同吸室负压、吹种正压下,分层充种室对排种器排种性能的影响。试验结果表明,在吸种盘转速为30 r/min、吸室负压为1.6 k Pa、送种正压为0.1 k Pa、采用分层充种室的条件下,该排种器排出(1~3)粒/穴种子的概率为95.4%,空穴率为1.53%,大于4粒/穴的概率为3.07%,其中排出1粒/穴种子的概率为17.32%,2粒/穴种子的概率为58.72%,3粒/穴种子的概率为19.36%;与前期开展的水稻气力式精量穴播排种器排种性能试验结果相比较,增设分层充种室后,排种器播种精度提高。该研究表明,减小排种器中水稻种子之间的挤压力和摩擦力,改善种子的流动性,从而使吸种盘上吸孔对种子的吸附能力增强,是提高水稻气力式精量穴播排种器的性能的重要途径。该文为水稻气力式排种器结构优化与性能提升研究提供了重要参考。

Design and experiment of stratified seed-filling room on rice pneumatic metering device

Abstract: The technology of rice's mechanical direct seeding can significantly reduce the consumption of manpower and material resources, and meanwhile maintain the production of rice. Super hybrid rice is a kind of hybrid rice and its tillering ability is stronger than the general hybrid rice. Due to the characteristics of high tillering capacity of super hybrid rice, the sowing quantity is required to be 1-3 seeds for each hole when super hybrid rice seeds are directly seeded to the field by the drilling machine, so as to ensure the high precision of seeding and high rate of field seedling emergence. In order to meet the requirement of 1-3 seeds for each hole using the precise hill-drop drilling technique, a seed-filling stratified room was designed, which was between the seed-metering device and the seed box on pneumatic feed mechanism for precision rice hill-drop sowing. It also aimed at improving the liquidity of seeds and raising the seeding precision, the liquidity of rice seed would reduced after accelerating germination. This the reduction of the liquidity of rice seed after accelerating germination had so bad effects on filling process that it limited the improvement of metering performance. Indic hybrid Peizataifeng was taken as the research object, and the impacts of the seed-filling stratified room on the performance of the pneumatic feed mechanism was studied by the single-factor experiment and orthogonal experiment in this paper. These experiments were carried out under different negative pressures for sucking seeds and positive pressures for blowing seeds. The experimental results showed that there existed an optimization condition on the capability of the metering device to meet the needs of the production. The probability about the quantity for each hill was used to evaluate the capability of the pneumatic precise metering device. The seed-filling stratified room consisted of a barrel and two seed-guiding plates. The cross-section of the barrel was the square with 50 mm per side. There were the chutes on the lining of the barrel, which were 1.1 mm wide. Seed-guiding plates were 1 mm thick, which were connected with the barrel by chutes. The two seed-guiding plates formed an angle of 45 degrees. The optimization condition was that the sucking plate's rotation speed was 30 r/min, the negative pressure for sucking seeds was 1.6 kPa and the positive pressure for blowing seeds was 0.1 kPa. With the seed-filling stratified room, the probability of 1-3 seeds per hill for the metering device was 95.4%; in addition, the probability of empty seed was 1.53%, and the probability of greater than or equal to 4 seeds was 3.07%. Under the same condition, the probability of one seed per hill for the metering device was 17.32%; in addition, the two-seed probability was 58.72% and three-seed probability was 19.36%. Compared with the existed researches, the results showed that the seed-filling stratified room between the seed-metering device and the seed box on pneumatic feed device, had a good influence on the precision of the pneumatic seed-metering device, improved the fluidity of the seeds and decreased the friction force and extrusion force among the seeds. This study provides an important reference for the structure optimization and the performance improvement of the pneumatic metering device.